Conventionally, there are well known various types of paper sheet storing units in each of which the paper sheet taken in the paper sheet storing unit is stored. For example, in a banknote processing unit disclosed in Patent Document 1, a pouch is attached between a first frame and a second frame, and the pouch is retained in an opened state by the first frame and the second frame. In the banknote processing unit, when an upper opening of the pouch is sealed after a banknote is stored in the pouch, the first frame is pulled onto a front side of the banknote processing unit to abut the first frame and second frame on each other, thereby sealing the upper opening of the pouch. After the upper opening is sealed, the first frame is further drawn onto the front side, the pouch in which the upper opening is sealed is taken out from the inside of the banknote processing unit, and finally the pouch is collected. An adhesive surface is formed in an inner surface of the pouch, and the upper opening of the pouch is sealed by adhesion of the adhesive surface. After the upper opening is sealed, the first frame is further drawn onto the front side, the pouch in which the upper opening is sealed is taken out from the inside of the banknote processing unit, and finally the pouch is collected.
In a banknote processing unit disclosed in Patent Document 2, a banknote storing bag (the pouch) is set in a banknote storage container, and the banknote taken in the container is stored in the banknote storing bag by free fall using transport means.